Roller grinding mill



1956 A. E. HAWKINS ETAL 2,759,774

ROLLER GRINDING MILL Filed March 4, 1954 3 Sheets-Sheet l i Z7 I|| |1 h"; ,r 1 27 1 i r 1 INVENTORS. ALBERT E. HAWKINS 8x GOSTA R. LINDEN Aug. 21, 1956 Filed March 4, 1954 FIG. 3.

A. E. HAWKINS ETAL ROLLER GRINDING MILL 3 Sheets-Sheet 2 :11 Ill FIG. 4.

INVENTORS ALBERT E. HAWKINS 8 GOSTA R. LINDEN ATTOZ/Vfy Aug. 21, 1956 w s ETAL 2,759,774

ROLLER GRINDING MILL Filed March 4, 1954 5 Sheets-Sheet 5 INVENTORY. ALBERT E. HAWKINS 8| GOSTA R. LINDEN BY A TTOZIVf/S' United States Patent ROLLER: GRINDING lVIILL Albert E. Hawkins, Wood Ridge, and Gosta R. Linden,

Park Ridge, N. J., assignors to J. M. Lehmann Company, Inc., Lyndhurst, N. J., a corporation of New York Application March 4, 1954, Serial No. 414,035

Claims. (Cl. 308-59) This invention relates to improvements in roller grmding mills which are suited for grinding materials 1n the wet or flowable state, such as cocoa, inks, paints, pigments and the like. More particularly the invention relates to improvements in grinding mills of the type wherein a plurality of grinding rollers are disposed n tram w th their axes parallel to each other, and wherein the relatrve positions of the rollers. are adjustable to vary the distances between them and change their operatmgpressures in order to adapt the mill for different operations on a material, and for the treatment of different materials.

Generally in these mills the roller at one end of the train is journaled in fixed bearings, while. the bearings of all of the other rollers in the train are adjustable in relation thereto, or in a mill having three or more grinding rollers one of the intermediate rollers may be journaled in fixed bearings and the bearings of the rollers on each side of the fixed roller are adjustable in relation thereto. The first type is known as a floating roller mill, or as a. two point; control mill, because the adjustment for all of the grinding rollers is made merely by adjustmg the two bearings of the movable end roller. A mill of thistype is disclosed in the Jack Patent No. 2,606,080, August 5, I952. The second type of mill is known as a four point control mill because both bearings for each of the end rollers must be adjusted to provide the desired relation between the movable rollers and the fixedintermediate: 7

roller. A mill of this type is disclosed in the Linden P'atentNo. 2,592,048, April 8', 1952'.

This invention has for its object the provision of improvements in this art. One of the objects is to provide a grinding mill having a train of at least three rollers, all of' whichare mounted to be movable in the millframe toward and away from each other, and in which the spac ingbetween all of the rollers may be controlled, electively, either by adjusting one of the end rollers, or by locking an intermediate roll'er of the train relative to the frame and adjusting the rollers on both sides relative thereto. Another objecttis to provide such a mill in which the said intermediate roller may be quickly and easily locked and unlocked; electively, against movement in the frame. Another object' is to provide means forelectivelylocking an intermediate roller in such a grinding mill. Otherobjects and features of novelty of the invention will be apparent from the following description of an illustrative embodiment thereof shown in the accompanying drawings, wherein:

Figure 1- is atop plan view'of' a mill havingthree; rollers in train;

Figure 2 is a side elevation of the mill shown in Figure 1;

Figure 3 is a fragmentary enlarged view of the upper part of Figure 2,, with portions of the mill frame and the bearing for the center roller broken away in vertical Section;

Figure. 4. is a; horizontal sectional view taken. substantiallv on the line 4-4 of Figure 3, with alpontion of the 2,759,774 Patented Aug. 21, 1956' vertical locking pin broken away to a lower section where the pin passes through the bearing;

Figure 5 is a fragmentary enlarged view looking down on the head of the locking pin for the bearing;

Figure 6 is a fragmentary vertical section through the frame of the mill taken substantially on the line 66 of. Figure 3;

Figure 7 is a fragmentary enlarged: view of the upper right-hand portion. of a mill as in Figure 2,,v but showing a dilferent type of bearing locking mechanism;

Figure 8 is a fragmentary vertical, section taken substantially on the line 8-8 of Figure 7;.

Figures 9 and 10 are fragmentary sections taken substantially on. the line 9--9" of Figure 8, Figure 9 showing thelocking bar turned to free the bearing of the roller for movement in the guideway of its associated frame memher, as in Figure 8, and Figure 10 showing. the locking. bar turned through an angle of to lock the bearing against movement relative to the frame member; and

Figure 11 is an exploded perspectiveview showing the parts of the mechanism for locking and unlocking the bearing relative to the frame.

In treating certain materials in grinding mills which include three or more grinding rollers in train it may be desirable to have the bearings of an intermediate roller fixed relative to the frame, and to adjust the bearings of the rollers. on each side of the: fixed roller so as to permit difi erential spacings and: pressures between. the said intermediate: roller and the side rollers. In treating other materials where. differential spacings. and pressures between. the grinding rollers are not important it may be desired tohave the bearings. of one of'the end rollers of the train fixed relative to the frame so: as to limit the adjustment to the bearings of the other end roller, the intermediate roller or rollers floating between the two end rollers.

In the grinding mill of the present. invention the bearings. of all of the grinding rollers are slidably mounted in the frame members, means: are provided for individually adjusting the. bearings of each. of the end rollers in relation to an intermediate roller, and means are provided for quickly and easily locking. and unlocking the bear ings of. the said intermediafie roller relative to the frame members to permit operation of the mill, electively', either by two point. control or by four point control.

While theinvention may be used in a: mill having'three' rollers, or in a. mill having: more than three rollers, itv will be.- suflicienti for the purpose of illustrating and de-- scribing the invention: to; refer to its embodiment in a three-roller mill. The illustrative embodiment discloses a mill in which: the: rollers. are. arranged with their axes in a common horizontalplane, but it will be evident that the. rollers. may 'be arranged in.- an inclined plane; or in avertical plane, and furthermore: that all rollers of the train need not be in a. common plane.

In. the drawings the three. rollers 15, 16, 17', arranged in; train with their axes paralleL. may be driven by a motor. 118 through, a. drive; chain connecting the motor shaft. to a sprocket. on the end: of one'of the rollers, here the roller. 17. The other two rollers 16' and 15 are in turn driven by roller 17 by means oii'gears, not shown, on: the ends of the rollers, the. roller 16 beingv driven at a slowor speed than roller 17,. and; the roller-:15 being driven at a, still lower speed than roller 16. The gears: and the known type which permit driving; of the rollers smoothly and quietly in. all relatively adjusted. positions of the rollers. Therollersmay beprovided in known manner with connections. and pipes; for supplying cooling fluidv thereto.

Each. end. of. each ofi theroll'ers isi journaled with suitable anti-friction members in a bearing housing, usually referred! to; herein. merely' as: a. bearing, the. bearings: for roller 15 being; denoted 20,2 1,. the=bearings for roller 16-- 3 being denoted 22, 23, and those for roller 17 being denoted 24, 25. The bearings 20, 22 and 24 are each movable along a guideway in the frame member 26 of the mill and the bearings 21, 23 and are each movable along a similar guideway in the frame member 27, so as to permit movement of the rollers toward and away from each other. In the illustrative embodiment the bearings in each frame member are slidably mounted in a common guideway with the axes of all of the rollers in a common plane, but as already indicated this is not essential to the invention.

For adjustment of the end or flanking rollers 15, 17 relative to the intermediate or center roller 16, each bearing of each of the end rollers may be adjusted in known manner in its guideway by a screw or screw-jack shaft 23 and the adjusting handle 29 secured thereon. This adjusting mechanism may be of the type disclosed in the aforementioned Linden Patent No. 2,592,048, for example.

\Vhen the mill is to be operated by two point control, the adjustment of the rollers relative to each other will be made by adjusting the bearings of only one of the end rollers. Preliminary to such operation the bearings for the other end roller desirably will be adjusted to predetermined positions in their frame members and for that purpose a position indicator is provided for the end roller which is to function as a fixed roller.

Connected to the inner side of each bearing of such end roller, roller 15 in the illustrative embodiment, is a pointer 36 which is offset laterally so as to extend over the surface of the frame member of the mill. Secured on the frame member is an indicator plate 31 having a graduation thereon, the relative locations of the indicator plate on the frame and of the pointer on the bearing being such that the bearing is in the desired predetermined position when the tip of the pointer coincides with the graduation. While the position indicator is illustrated on the slow roller 15, it may be located on the fast roller 17, if desired.

Located between the bearings of the center roller 16, and the bearings of each of the flanking rollers 15, 17 are compression loading springs 32 which impart pressure biasing the flanking rollers away from the center roller. These springs are heavy enough to overcome the Weight of the rollers and the friction of the bearings in their guideways so as to separate the rollers by sliding them apart. For example, if the weight of the rollers is approximately a ton, it may be desirable to use about a 700 pound spring.

The loading springs 32 may be positioned between the bearings by means of oppositely disposed spring loading pins or collars 33, 34 secured on the bearings. Desirably restrictor means are provided between the bearings, associated with each loading spring, to limit the amount of the separation between the rollers effected by the springs. As shown, the spring supporting members 33, 34 are collars and the restrictor comprises a cap screw 35 extending slida'oly from inside the bearing for the end .roller, through the collar 33, and screw-threadedly engaging the bore of the collar 34. The cap screw 35 will be adjusted initially to permit the desired maximum separation between the bearings of the rollers and ordinarily will not require further adjustment. Since the unthreaded portion of the cap screw 35 is slidable in the collar 33, the screw does not prevent the bearings from being moved in their guideway toward each other.

The means for electively locking the bearings of the center roller 16 in their guideways will now be described in connection with Figures 36. In this embodiment, individual similar locking members are provided for the bearings at both ends of the center roller. Each lock ing member comprises a rotatably adjustable spindle or locking pin 36 which is fixed against movement relative to the frame member in the direction in which the bearing is movable.

The locking pin 36 is provided with means so that it may be turned between locking and non-locking positions, for example a hexagonal head 37 to be engaged by a Wrench. The locking pin passes downwardly through an indicator plate 33 and guide bushing 39 located on the top of the frame member 26. The locking pin extends between the journals of the rollers 15, 16, through an opening 40 in the flange 41 of the bearing 22, and has its lower end journaled in the guideway portion of the frame member 26.

As may be seen in Figure 4, the opening 40 is generally rectangular in shape, the longer dimension being pemendicular to the line of movement of the bearing 22 in its guideway and being equal to the diameter of the locking pin 36. The shorter dimension of this opening 40 is slightly less than the diameter of the locking pin. In order for the opening 40 to receive the locking pin 36 and permit rotation thereof the intermediate portions of the two longer sides of the rectangular opening bow outwardly on a radius corresponding to the radius of the locking pin, as shown in Figure 4.

That portion of the locking pin 36 which passes through the opening 40 in the flange 41 of the bearing 22 has oppositely disposed slots 42 in the side thereof. When the locking pin is turned to the position shown in Figures 3 and 4, these slots face the longer sides of the opening 4t} in the bearing flange and the bearing 22 is free to move back and forth in its guideway, the range of movement being determined by the depth of the slots 42. While this movement is limited, it will be entirely adequate for two point control operation of the mill.

When it is desired to operate the mill under four point control, one or both of the end rollers 15, 17 will be adjusted to bring the center roller 16 approximately to the preselected position Where it is to be locked in its guideway, and the two locking pins 36 then will be turned through an angle of During this turning of the locking pins the slotted portion of eac. pin will act as a cam to position the bearing exactly in the preselected position in its guideway and to lock the bearing against movement in its guideway. This having been accomplished, the mill now is ready for four point control operation.

To reset the machine for two point control operation. all that is required is to turn the two locking pins 36 through an angle of 90, thus releasing the bearings for the center roller so that they can move in their guideways.

Figures 7-11 disclose a modified locking mechanism for electively locking the center roller 16 in preselected position. Instead of individual locking pins for the two bearings of the center roller a single locking bar 43 extends transversely of the mill and is journaled in the frame members 26, 27. One end of this locking bar extends outwardly through the frame member 26 and has secured thereon means for turning the locking bar, for example a hand crank 46. Secured on the frame member adjacent the crank 46 is an indicator plate 47.

This locking bar 43 passes through aligned contradisposed matching recesses 45, 44 in the bearings of the center roller and the guideways of the frame members, these recesses being located between the sliding surfaces of the bearings and the guideways. The recess in the guideway is shown at 44 and the recess in the bearing is shown at 45, in Figures 9-11.

Opposite each of the recesses 45 in the bearings 22, 23, the locking bar 43 has a slot 48 in the side thereof, the depth of these slots being one-half the diameter of the locking bar. When the locking bar is turned to the position shown in Figures 8 and 9, the slotted portions of the locking bar lie wholly within the recesses 44 in the bearing guideways and the bearings of the center roller are free to move in the guideways. In other words, the mill is in condition for two point control operation.

When it is desired to condition the mill for four point control operation one or both of the end rollers are adjusted until the recesses 44, 45 are approximately oppo site each other. Then by turning the crank 4d the locking bar 43 is rotated through an angle of 18W. This causes the slotted portions 4Q or the iocki'ng bar to exert a camm-ingactionagainst the Walls of the recesses 45 to position the bearings exactly in the preselected positions in their guidewa-ys and to lock the bearings against further movement. This is illinltratetl in Figures and- 11', and the mill then will be condition for four point control operation.

To reset the mill for twopoint control operation it is necessary merely to: again turn the locking bar through an angle of 180, thereby turning the slotted. portions oi the locking. bar out from the: recesses 45 into the re cesses 44' and freeing: the bearings for movement in their guideways.

In operating the milli shown. the drawings, the material to be ground is delivered: between the: rollers 15, 16, above: the line of contact therebetween. Thin retain ing strips or plates 49" of: brass. or other suitable: material are. snugly held by mechanism 50 against these rollers adjacent their ends to prevent escapeofi material at the ends of the rollers. As the rollers revolve, minder two point control operati'om the material which passes between rollers 15 and 16 and adheres: to the. surface at faster roller 16 will be transferred to tiwe stillf faster roller 17, from which it will be scraped. off. by a'km'fie: on the inner edge of a discharge chute 51. By'utilizing. four'poim control operation, i. c. with the center roller locked, it is: possible to operate machine illustrated with. the rollers 15, 16 closed together for a mixing run and. with the delivery roller 117 adjusted to boom of engagement. Then the mill can be quickly changed to two pointv con trol operation, i. e. with the center. roller floating, when it is desired tohave the roller 16 engaged by the roller 17 and begin, delivery. Applicants have; provided a floating roller mill having the advantages of a fixed: intermediate roller mill.

The invention herein disclosed may be variously moditied and embodied within the scope of the subjoined claims.

We claim:

1. A roller grinding mill comprising at least three rollers arranged in train, a bearing at each end of each roller, frame members at opposite sides of the mill in which all of said bearings are movable to permit movement of the rollers toward and away from each other, means to adjust the position of each of the rollers flanking an intermediate roller of the train relative to the said intermediate roller, and means to lock and unlock the bearings of the said intermediate roller, electively, against movement in the frame members, said last mentioned means comprising cam means for positioning and holding the bearings of the intermediate roller in preselected positions in their guideways.

2. A roller grinding mill comprising at least three rollers arranged in train, a bearing at each end of each roller, frame members at opposite sides of the mill in which all of said bearings are movable to permit movement of the rollers toward and away from each other, means to adjust the position of each of the rollers flanking an intermediate roller of the train relative to the said intermediate roller, means to lock the bearings of the said intermediate roller, electively, against movement in the frame members, compression loading springs located between the bearings of the said intermediate roller and the bearings of each of the said flanking rollers to impart pressure biasing the flanking rollers away from the intermediate roller, and adjustable restrictor means between the bearings of the said intermediate roller and the bearings of the said flanking rollers to limit the amount of the separation between the said intermediate roller and its flanking rollers eifected by the said springs.

33. A roller grinding mill according to claim 2, including position indicator means on the bearings of one of said flanking rollers, and cooperating position indicator means 6 V l on, the" frame members to facilitate adjusting such flank? ingroller to a preselected position relative, to the frame members.

4 A roller grinding: mill comprisingat least three, rollers arranged in train, abearing' at each end' of each roller, frame members at opposite sides of the mill in which all of said bearings are movable to permit movement of the rollers toward and away from each other, meansto adjustthe position of each of the rollers flanking an intermediate roller of the train relative to the said intermediate roller, means to lock the bearings of the intermediate roller, electively, againstmovement in the framemembers, position indicator means on the bearings of one of said flanking rollers, and cooperating position indicatormeans on the frame members to facilitate adjusting'said flanking roller to a preselected position relative to the frame members;

5. A roller grinding mill accordingto claim 1, in which the means for locking a bearing of the said intermediate rolier against movement in its frame member includes a locking member which is" fixed against movement relative to the frame member in the direction in which the bearing is movable, and inwhich the bearing for the said intermediate roll'er has an opening engageable bythe locking member when the intermediate roller is in a preselected position relative to the frame member to hold the bearing of the intermediate roller against movement in the frame member, and including means for actuating the locking member electively tolocking and non-locking positions.

6. A roller grinding mill comprising at least three rollers arranged in train, a bearing at each end of each roller, frame members at opposite sides of the mill in which all of said bearings are movable to permit movement of the rollers toward and away from each other; means" to adjust the position ofeaclrof the rollers fl'anking' an intermediate roller of the train relative to the said intermediate roller, means to lock the bearings of the said intermediate roller, electively, against movement in the fian-re members, the means for locking a bearing of the said intermediate roller against movement in its frame member including a locking memberwhich is fixed against movement. relative to the frame member in the. direction imwhich the bearingis' movable, the bearing. for the said intermediate roller having 31]., opening engageaible by the locking member when the intermediate roller is in a preselected position relative to the frame member to hold the bearing of the intermediate roller against movement in the frame member, means for actuating the locking member elcctively to locking and non-locking positions, the locking member being a rotatably adjustable spindle which has a cam portion disposed opposite the said opening in the bearing of the intermediate roller, so that when the spindle is turned to one position the locking member engages the said opening to position the bearing accurately with respect to its frame member and to hold the bearing against movement relative to the frame member, and when turned to a different position permits the bearing to slide in the frame member.

7. A roller grinding mill comprising at least three rollers arranged in train, a bearing at each end of each roller, frame members at opposite sides of the mill in which all of said bearings are movable to permit movement of the rollers toward and away from each other, means to adjust the position of each of the rollers flanking an intermediate roller of the train relative to the said intermediate roller, means to lock the bearings of the said intermediate roller, electively, against movement in the frame members, the means for locking a bearing of the said intermediate roller against movement in its frame member including a locking member which is fixed against movement relative to the frame member in the direction in which the bearing is movable, the bearing for the said intermediate roller having an opening engageable by the locking member when the intermediate roller is in a preselected position relative to the frame member to hold the bearing of the intermediate roller against movement in the frame member, means for actuating the locking member electively to locking and non-locking positions, the locking member being a rotatably adjustable round spindle which has a slot cut in the side thereof opposite the said opening in the bearing of the said intermediate roller, so that when turned to one position the locking member engages the said opening to hold the bearing against movement relative to the frame member and when turned to a different position permits the bearing to move in the frame member.

8. A roller grinding mill comprising at least three rollers arranged in train, a bearing at each end of each roller, frame members at opposite sides of the mill in which all of said bearings are movable to permit movement of the rollers toward and away from each other, means to adjust the position of each of the rollers flanking an intermediate roller of the train relative to the said intermediate roller, means to lock the bearings of the said intermediate roller, electively, against movement in the frame members, the means for locking a bearing of the said intermediate roller against movement in its frame member including a locking member which is fixed against movement relative to the frame member in the direction in which the bearing is movable, the bearing for the said intermediate roller having an opening engageable by the locking member when the intermediate roller is in a preselected position relative to the frame member to hold the bearing of the intermediate roller against movement in the frame member, means for actuating the locking member electively to locking and non-locking positions, each of the bearings of the said intermediate roller and the associated frame members having aligned openings in which there are rotatably adjustable locking pins, each of the locking pins having oppositely disposed slots cut in the side thereof adjacent the said bearings, and means for rotatably adjusting the locking pins to move the slotted portion of the bar into and out of locking engagement with the opening in the associated bearing.

9. A roller grinding mill comprising at least three rollers arranged in train, a bearing at each end of each roller, frame members at opposite sides of the mill in which all of said bearings are movable to permit movement of the rollers toward and away from each other,

means to adjust the position of each of the rollers flanking an intermediate roller of the train relative to the said intermediate roller, means to lock the bearings of the said intermediate roller, electively, against movement in the frame members, the means for locking a bearing of the said intermediate roller against movement in its frame member including a locking member which is fixed against movement relative to the frame member in the direction in which the bearing is movable, the bearing for the said intermediate roller having an opening engageable by the locking member when the intermediate roller is in a preselected position relative to the frame member to hold the bearing of the intermediate roller against movement in the frame member, means for actuating the locking member electively to locking and non-locking positions, both bearings of the said intermediate roller and the frame members having aligned, contradisposed matching recesses between their moving surfaces, the locking member being a bar extending transversely of the mill through the aligned recesses, the bar having slots cut in the side thereof adjacent the said bearings, and being rotatably adjustable relative to the frame members to move the slotted portion of the bar into and out of locking engagement with the said bearing members.

10. A roller grinding mill comprising three rollers arranged in train, a hearing at each end of each roller, frame members at opposite sides of the mill in which all of said bearings are movable to permit movement of the rollers toward and away from each other, means to adjust individually the position of each of the flanking rollers relative to the center roller, means to lock the bearings of the center roller, electively, against movement in the frame members, compression loading springs located between the bearings of the center roller and the bearings of each of the flanking rollers to impart pressure biasing the flanking rollers away from the center roller, and adjustable restrictor means between the bearings of the center roller and the bearings of the flanking rollers to limit the amount of the separation between the center roller and the said flanking rollers.

References Cited in the file of this patent UNITED STATES PATENTS 1,699,641 Vasel Jan. 22, 1929 

